1. Field of the Invention
The invention pertains to a rotary joint which delivers a mixed fluid axially through a high-speed rotating shaft and prevents the mixed fluid from leaking to the surrounding area.
2. Description of the Prior Art
For some processes, a mixed fluid has to be delivered axially through a rotating shaft. Therefore, it requires a rotary joint to supply the mixed fluid while the shaft is rotating. However, traditional rotary joints are used in the environment for supplying only a pure fluid (for example water, oil, etc.) as disclosed by several patents, such as U.S. Pat. Nos. 5,303,959, 5,226,677 and 5,209,526. The structural designs of these rotary joints are only suitable for supplying a pure fluid and not for supplying a mixed fluid such as grinding materials, impure water and so on. Once those rotary joints supply a mixed fluid with solid materials such as grinding materials, impure water and so on, impurities will easily leak to the bearing structure and cause it damage and failure. Furthermore, rotating wear causes some parts of rotary joints to malfunction so that those parts are difficult or impossible to be replaced. Therefore, the present invention overcomes these structural defects. After continuous tests and experiments, the inventor has developed a leakproof rotary joint which totally eliminates traditional structural defects.